The unrecognized separatist mini-states in eastern Ukraine, the Donetsk and Luhansk People’s Republics, were rescued from a near-death experience last month, when a Russian military incursion routed the Ukrainian Army as it appeared close to completing a campaign to wipe the rebels out.

A cease-fire that preserved the regions’ semiautonomous status was signed on Sept. 5.

In the relative lull in fighting since, rebel leaders have busily set about building the sort of neo-Soviet states that have cropped up in other pro-Russian enclaves in the former Soviet Union: in Abkhazia and South Ossetia, both on the border between Russia and Georgia, and in Transnistria.

If a stalemate similar to these “frozen conflicts” were to last in eastern Ukraine, it could make eventual reintegration with the rest of the country difficult, if not impossible.

“There is a lot of pompous celebration of the victory over fascism, a love for Soviet abbreviations, symbols and monuments,” said Vladimir Solovyov, a journalist with the Russian newspaper Kommersant, who was raised in Transnistria, which is sometimes called a sliver of the Soviet Union.

Such Soviet nostalgia may seem farcical to Westerners, yet where it has been institutionalized in these pro-Russian enclaves, it has been well received by the citizenry.

“They accept the repression because they know nothing else,” said Mr. Solovyov, who moved away when he was 16.

“People don’t want to talk politics because nobody wants to be fired and lose the small salary they receive. We had a lot of elections, but the same person always won.”

While there may be a cartoonish hue to the anachronisms here and elsewhere in the former Soviet sphere where unreformed Communist institutions have popped up — in Belarus or Turkmenistan, for example — they mask the darkly serious human rights abuses that critics say are endemic in such systems.

Dmytro O. Potekhin, a Ukrainian political activist, was held for 48 days in a detention center in Donetsk that was set up in an industrial-themed modern art center called Isolation.

To clear space for the prison, fighters with the Donetsk People’s Republic smashed art in the gallery, including a large outdoor installation of mirrors that they found objectionable.

The interior layout had not changed much from its days as a gallery, Mr. Potekhin said, other than the addition of a few buckets for use as toilets, a horrible stench and blood-chilling wails.

“It was absolutely terrible,” he said in a recent interview.

He said he was subjected to mock executions and questioned in a room with children’s art hanging on the walls.

Rebels kept, by his estimation, hundreds of detainees in the locked gallery spaces, where the screams from nightly beatings echoed through the building.

“It’s a combination of 1917 and 1937,” he said, referring to the Bolshevik Revolution and one of the darker years of Stalin’s reign.

Military tribunals have ordered the incarceration of an estimated 1,000 people.

“It’s a police state with no court system,” Mr. Potekhin said.

“I was kept because there is no system of releasing people.

There is a very advanced, very violent system of capturing people, but no system to release them.”

The leadership of the Donetsk People’s Republic is drawn from Russian volunteers and local residents whose pro-Soviet political views were once on the fringe but are suddenly in demand.

Through the lean years of market-oriented and pro-democratic overhauls, Boris O. Litvinov, the chairman of the Supreme Soviet and a self-described “committed Communist,” made a living with odd jobs unrelated to his university degree in Marxist Leninism.

He played bass guitar in a cafe, hawked goods as a salesman and taught at a community college until, improbably, his hour finally arrived.

“Over the past 23 years Ukraine created a negative image of the Soviet Union,” Mr. Litvinov, 60, said in an interview.

“The Soviet Union was not about famine and repression. The Soviet Union was mines, factories, victory in the Great Patriotic War and in space. It was science and education and confidence in the future.”

Still, Mr. Litvinov, who said he consulted often with officials in Moscow, insisted the new republic would not repeat Soviet repression.

As part of the so-called New Russia, he said the People’s Republic used as its template the laws of contemporary Russia, not the Soviet Union.

The republic intends to integrate with Russia and the Eurasian Union, a Russian-backed trade group that includes Belarus and Kazakhstan, he said.
Mr. Litvinov said that extrajudicial imprisonment here was a temporary wartime expedient, and that a court system would be up and running by December.

After elections scheduled for Nov. 2, he said, the Supreme Soviet would be renamed the People’s Soviet.

But Mr. Litvinov said some of the excesses, like referring to the security force as the N.K.V.D., were not to be taken seriously.

“Some military men say, ‘I am from the N.K.V.D.,’ but it’s just bravado,” he said.

Soviet revivalism is not the only underpinning of the uprising here. An icon in Mr. Litvinov’s office, a gift from a Russian politician, illustrates the religious and nationalist elements of the ideology behind New Russia.

Still, the Soviet influence is clear. Fyodor D. Berezin, a deputy defense minister, who before the uprising was an author of science fiction novels, described the system of government the Donetsk People’s Republic as aiming to build as “military Communism.”

The Isolation art space, where he once held talks as an author, is better used as a prison and garrison, he said, because the art there was “beautiful but senseless.”

“Yes, we have a parliament and so on, but we will rule with military methods,” he said in an interview.

“It’s a necessary situation. Democracy, that beautiful structure of society, is possible when resources are abundant. We don’t have that now. Winter is here.”